Buggy code:
protected final ResourceManager resourceManager ; private final Map < String , Variable > variables = new HashMap < String , Variable > ( ) ; private final Map < String , Variable > globalVars = new HashMap < String , Variable > ( ) ; private ProgressMonitor monitor ; private Resource currentResource ; protected final TypeSystemImpl typeSystem ; protected ExceptionHandler exceptionHandler ; protected NullEvaluationHandler nullEvaluationHandler = null ; public ExecutionContextImpl ( ) { } public ExecutionContextImpl ( TypeSystemImpl ts ) { } public ExecutionContextImpl ( Map < String , Variable > globalVars ) { } public ExecutionContextImpl ( TypeSystemImpl ts , Map < String , Variable > globalVars ) { } public ExecutionContextImpl ( ResourceManager resourceManager , TypeSystemImpl typeSystem , Map < String , Variable > globalVars ) { } public ExecutionContextImpl ( ResourceManager resourceManager , Resource resource , TypeSystemImpl typeSystem , Map < String , Variable > variables , Map < String , Variable > globalVars , ProgressMonitor monitor , ExceptionHandler exceptionHandler , List < Around > advices , NullEvaluationHandler neh2 , Map < Resource , Set < Extension > > extensionPerResourceMap ) { } public void registerMetaModel ( final MetaModel mm ) { } public Operation findOperation ( final String name , final Object target , final Object [ ] params ) { } public Property findProperty ( final String name , final Object target ) { } public Type [ ] findTypesForPrefix ( final String prefix ) { } public Type [ ] getAllTypes ( ) { } public Set < String > getNamespaces ( ) { } public Type getBooleanType ( ) { } public Type getCollectionType ( final Type innerType ) { } public Type getFeatureType ( ) { } public Type getIntegerType ( ) { } public Type getListType ( final Type innerType ) { } public Type getObjectType ( ) { } public Type getOperationType ( ) { } public Type getPropertyType ( ) { } public Type getRealType ( ) { } public Type getSetType ( final Type innerType ) { } public Type getStaticPropertyType ( ) { } public Type getStringType ( ) { } public Type getType ( final Object obj ) { } public Type getTypeForName ( final String name ) { } protected String [ ] getImportedNamespaces ( ) { } public Type getTypeType ( ) { } public Type getVoidType ( ) { } public ExecutionContextImpl cloneContext ( ) { } public void setFileEncoding ( final String encoding ) { } public Variable getVariable ( final String name ) { } public Map < String , Variable > getVisibleVariables ( ) { } public Map < String , Variable > getGlobalVariables ( ) { } public ExecutionContext cloneWithVariable ( final Variable v ) { } public ExecutionContext cloneWithoutVariables ( ) { } public ExecutionContext cloneWithResource ( final Resource ns ) { } public ExecutionContext cloneWithoutResource ( ) { } public ExecutionContext cloneWithoutMonitor ( ) { } public Resource currentResource ( ) { } protected Map < Resource , Set < Extension > > allExtensionsPerResource = null ; public Set < ? extends Extension > getAllExtensions ( ) { } public Extension getExtensionForTypes ( final String functionName , final Type [ ] parameterTypes ) { } public Extension getExtension ( final String functionName , final Object [ ] actualParameters ) { } public void setMonitor ( ProgressMonitor monitor ) { } public ProgressMonitor getMonitor ( ) { } public void preTask ( Object element ) { } public void postTask ( Object element ) { } public void handleRuntimeException ( RuntimeException ex , SyntaxElement element , Map < String , Object > additionalContextInfo ) { } public ResourceManager getResourceManager ( ) { } protected List < Around > registeredExtensionAdvices = new ArrayList < Around > ( ) ; public void registerExtensionAdvices ( final String fullyQualifiedName ) { final XtendFile ext = ( ( XtendFile ) ( resourceManager . loadResource ( fullyQualifiedName , FILE_EXTENSION ) ) ) ; if ( ext == null ) { throw new IllegalArgumentException ( ( ( "Couldn't<seq2seq4repair_space>find<seq2seq4repair_space>extension<seq2seq4repair_space>file<seq2seq4repair_space>'" + fullyQualifiedName ) + "'" ) ) ; } final List < Around > as = ext . getArounds ( ) ; for ( Around around : as ) { if ( registeredExtensionAdvices . contains ( around ) ) { <START_BUG> ExecutionContextImpl . log . warn ( ( ( "advice<seq2seq4repair_space>" + ( around . toString ( ) ) ) + "<seq2seq4repair_space>allready<seq2seq4repair_space>registered!" ) ) ; <END_BUG> } else { registeredExtensionAdvices . add ( around ) ; } } } public List < Around > getExtensionAdvices ( ) { } private final TypesComparator typesComparator = new TypesComparator ( ) ; private Extension advise ( Extension element ) { } class ExtensionAdvisor implements Extension { private final Extension delegate ; private final Around advice ; public ExtensionAdvisor ( Around advice , Extension delegate ) { } public Object evaluate ( Object [ ] parameters , ExecutionContext ctx ) { } public void analyze ( ExecutionContext ctx , Set < AnalysationIssue > issues ) { } public int getEnd ( ) { } public ExtensionFile getExtensionFile ( ) { } public String getFileName ( ) { } public List < DeclaredParameter > getFormalParameters ( ) { } public int getLine ( ) { } public String getName ( ) { } public List < String > getParameterNames ( ) { } public List < Type > getParameterTypes ( ) { } public Type getReturnType ( Type [ ] parameters , ExecutionContext ctx , Set < AnalysationIssue > issues ) { } public Type getReturnType ( ) { } public Identifier getReturnTypeIdentifier ( ) { } public int getStart ( ) { } public String getNameString ( ExecutionContext context ) { } public void init ( ExecutionContext ctx ) { } public boolean isCached ( ) { } public boolean isPrivate ( ) { } public void setExtensionFile ( ExtensionFile file ) { } public String toOutlineString ( ) { } @ Override public String toString ( ) { }

Fix:
ExecutionContextImpl . log . warn ( ( ( "advice<seq2seq4repair_space>" + ( around . toString ( ) ) ) + "<seq2seq4repair_space>already<seq2seq4repair_space>registered!" ) ) ;